Note: Descriptions are shown in the official language in which they were submitted.
GR 91 P 74L19
LOAD SASE ~r7TTH T3S'x'EGRAh ~IR..E Ia'DG
AIdY3 ~TRE IaUCg RETAINER
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention is directed to electrical power
distribution devicest particularly load bases which provide
electrical connection between a fuse and an electrical cable that
is connected to a load.
_Description of Art
Electrical distribution devices often utilize fuses for
circuit protection devices. Load bases, sometimes also referred
1p to as fuse blocks, are used to provide electrical continuity from
an electrical cable to the fuse. In some applications, a load base
is used an each end of a fuse, i. e. , on .both the so-called load and
line ends of the fuse. In other applications, a disconnect switch
is used on the line end of the fuse and a load base is used on the
. load end of the fuse, i.e., the end closer to the device which
utilizes eledtrical power-
Kriown fuse bases and fusible switches generally have an
insulating base and a conduct°ive bus attached to the base which has
threaded apertures for attachment of a wire lug with a threaded
member, such as a machine screw. A load base has a fuse clip
attached to the conductive strip and electrical continuity is
established between a wire connected to a load and a fuse by
connection of the wire to the wire lug and insertion of a fuse
conductive end into the fuse clip. Fusible switches often have a
~5 line end similar to a load base and a set of stationary switch
terminals, attached to the conductive bus in lieu of a fuse clip.
The switch has a translatable blade contact assembly for completion
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of continuity with the stationary switch terminals and a fuse clip
is electrically connected to the blade contact assembly. Examples
of load bases and fusible switches are shown in LT. S. patents Nos.
3,293,3921 3,525,8351 3,840,7171 3,393'395: 4,288,138 and
4,302,43.
Known load bases and fusible switches require attachment of
the conductive bus to the insulating base with fasteners or by
molding the conductive bus into the base. Some types of load bases
and switches utilize fasteners for the dual purpose of mounting a
lug or fuse clip to the conductive bus and in turn retaining the
bus on the base. Removal of one of the fasteners causes
disassembly of the components from the base that are secured by
that fastener, and the components can be lost during field service.
Also, the requirement for a manufacturing facility to stock
and install during assembly separate fasteners for retaining the
lug to the conductive bus, the fuse clip to the conductive bus and
the conductive bus to the base increases manufacturing costs.
It is an object of the present invention to create a wire lug,..
which allocas direct attachment of a fu:ae clip thereto without the
need for an additional conductive bus strip or other like
components.
It is another object of the present invention to minimize the
number of components needed to establish electrical continuity
between an electrical wire and a conductive end of a fuse, to
minimize parts,'inventory and manufacturing costs, assembly effort
and discontinuities which may be caused by inadvertent component
separation.
It is an additional object of the present invention to create
a wire lug retainer which holds a wire lug in position relative to
a load base or disconnect switch housing after removal of a fuse
clip coupled to the lug'.
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20365-3174
SUMMARY OF THE INVENTION
The objects are attained by the wire lug of the
present invention, which comprises a unitary lug body having
an aperture for receipt, of a cable and a plat=form for direct
attachment of a fuse clip thereto.
Other aspects of the present invenl~ion are
directed to a wire lug retainer comprising a housing; at
least one channel formed in the housing for ;~lidable
insertion and capture of a wire lug; and a t=ranslatable
tongue attached to the housing proximal the channel. The
tongue has a first position which permits sl:idable insertion
of a lug into the channel and a second position which blocks
removal of a lug from the channel, while rem<~ining attached
to the housing in both positions.
The present invention is also directed to a load
base comprising a wire lug having a unitary :lug body with a
wire aperture for receipt of a cable. The lug also has a
platform. The load base also has a unitary housing having
at least one channel for slidable insertion and capture of
the wire lug, a translatable tongue attached to the housing
proximal the channel having a first position which permits
slidable insertion of the lug into the channel and a second
position which blocks removal of the lug from the channel.
A fuse clip is directly attached to the wire lug platform.
The wire lug is removeable when the fuse clip is not
installed.
In accordance with the present invention, there is
provided a load base comprising: a wire lug having a
unitary lug body with a wire aperture for receipt of a cable
and a platform; a housing having at least one channel for
slidable insertion and capture of the wire lug, the
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CA 02063131 2002-03-06
.20365-3174
housing having sidewalls projecting from opposite sides of
the channel for formation of a fuse clip chamber, where each
sidewall has at least one track with a detent: rib and the
load base has a reciprocable fuse pulley which rides in the
tracks; a translatable tongue attached to the housing
proximal the channel having a first position which permits
slidable insertion of the lug into the channel and a second
position which blocks removal of the lug from the channel,
where the tongue is a cantilever attached at one end thereof
to the housing and is translatable by biasing the tongue;
and a fuse clip directly attached to the wire lug platform;
where the fuse pulley includes two legs which ride in the
tracks, a cross member between the legs for abutment against
a fuse in the fuse clip when removing the fu:~e pulley, and a
ramped nib projecting autwardly from at least: one of the
fuse pulley legs toward the track for self-biased abutment
against the track detent rib when the fuse pulley is
reciprocated to a desired end position, but which is
inwardly biasable by exertion of additional x-eciprocation
pressure on the fuse pulley, so that the pul7_er is
selectively removable from the load base.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a t.op plan view of the load base of the
present invention showing sliding insertion of a wire lug of
the present invention into the load base.
Fig. 2 is a cross sectional, elevat:ional view of
the load base of Fig. 1 taken along 2-2 thereof.
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Fig. 3 is a front elevational view of the load base of Fig.
1.
Fig. 4 is a back elevational view of the load base of Fig. 1,
showing insertion of a fuse puller.
l0
Fig. 5 is a top perspective view of a unitary lug of the
present invention.
Fig. 6 is a fragmented view of a load base of the type of Fig.
1 shown with a fuse clip which accepts blade-type fuses.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the figures, like components are identified with identical
reference numerals. Referring to Fig. 1, the load base 10 of the
present invention preferably has a three-phase housing 12. which has
a unitary construe~tion formed of injection-molded plastic. The
housing 12 may also be manufactured of multiple fabrications, such
as separate single phases that are joined together. Housing 12 has
a channel 14 for each phase, preferably integrally formed in the
housing. Each channel 14 is defined by a channel floor l6, three
channel sidewalls 18, channel upper detents 20 and channel lower
detents 22. channel floor 16 also has channel floor aperture 24.~
Referring to Figs. 1 and 2, the housing 12 has a cantilever
like tongue 26 that is preferably integrally formed with the
housing 12. The tongue 26 is generally parallel with the ehannel
floor 16, but is biasable in a generally downwardly direction as
shown by the arrow A in Fig. 2.
Referring to Figs. 1-4, the housing 12 has sidewalls 28 which
form separate chambers for each of the three phases. The sidewalls
28 have tracks 30. The tracks 30 also have decent ribs 32 which
project outwardly from the tracks toward the chamber interiors.
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The housing 12 provides the structural support for the
electrical components which provide continuity between electrical
cable 34 and fuse 36. The housing 12 also insulates the phases
from each other to prevent short circuits and ground faults.
Referring to Figs. 1 and 5, wire lug 38 has a lug body 40
which preferably has a unitary cross section and is formed by
extrusion. The lug body 40 has a wire aperture 42 for receipt of
electrical wire 34 and a wire lug screw 44 for retaining the
electrical wire in the wire aperture 42. The lug body 40 forms a
platform 46 for direct attachment of a fuse clip 48. Specifically,
platform 46 has one' or more threaded or unthreaded platform
apertures 50, for receipt of a fuse clip threaded member, such as
screw 54 which may be of standard or self-tapping construction.
The wire lug 38 with integral platform 46 eliminates the need for
a separate conductive bus to interconnect the fuse clip 48 with the
lug 38.
. The fuse clip 48 shown in Figs. 1 through 4 is designed for
use in connection with cylindrical, barrel-type fuses, such as fuse.
36, which are often rated for current capacities below 100 amps.
The load base, unitary lug and luck retainer features of the present
invention are also applicable to larger capacity blade-type fuses,
which are often manufactured for capacities of 100 amps or more.
Common blade-type fuses are often rated at 100 and 200 amp
capacities.
As shown in Fig. 6, a fuse 60 is connected to a blade-type
fuse clip 62. The blade-type fuse clip 62 is in turn connected to
unitary wire lug 38 by screw 54 that is threaded or screwed into
platform aperture 50. Otherwise, the features of the present
invention can be practiced for 100 and 200 amp fuse applications
as they are with the smaller amperage fuse applications shown in
Figs. 1-4.
The load base 10, wire lug 38, lug retainer channel 14 and
tongue 26 of the present invention provide for simplified
manufacture and assembly of a load base or similar fusible switch
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structure. Desirably, the housing 12 is formed as a unitary mufti-
phase product by an injection-molding process utilizing a suitable
thermoplastic of any type well known and recognized in the art for
use in load base and switch applications.
After the housing 1.2 is molded, it can be easily assembled by
slidable insertion of the wire lug 38 of the present invention into
channel 14, as shown in the lower-most chamber of Fig. 1. After
lug 38 is inserted in channel 14 and tongue 26 snaps upwardly to
its unbiased, relaxed state, lug 38 is captured in the housing 12
and cannot inadvertently drop out of the base 10.
Next in the assembly, a fuse clip, such as fuse clip 48 in
Figs. 1°4 or fuse clip 62 of Fig. 6, is attached directly to the
lug platform 46 with screw 54. The screw 54 may be sized so that
its threaded shank does not protrude from the bottom of the lug
platform 46, but a longer screw may be used to protrude from the
bottom of platform 46 and into the corresponding channel floor
aperture 24. When the fuse clip 48 of Figs. 1 and 2 or 62 of Fig.
6 is installed, the lug 38 cannot be removed.
If desired, a reciprocable fuse puffer 64 can be inserted into
the tracks 30 after installation of the lug 38 and .fuse clip 48,
as is shown in Figs. 1 and 4. Referring to Fig. 4, the fuse pullet
64 has a pair of legs 66 and a tamped nib 68 which projects
outwardly from at least one, but preferably both of the legs &6
toward each track 30 and rides within 'the track. The nibs 68 abut
against the track decent rib 32 when the pullet 64 is reciprocated
to a desired end position. The fuse pulley 64 has cross member 70
between the legs 66 for abutment against fuse 36 when removing the
fuse.
The fuse pullet 64 nibs 68 and legs 66 are inwardly self
biasable by exertion of additional upward retraction pressure on
the pullet 64, so that when desired, the pullet is easily removable
from the load base 10, yet is retained sufficiently to avoid
inadvertent removal from the base. In the most downwardly (rest)
position of the fuse pullet 64, the bottoms of legs 66 are designed
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to rest against the surface onto which the load base to is mounted.
Thus the mounting surface, rather than any portion of the load base
limits the down stroke of the fuse pulley ~4.
The foregoing description of the preferred embodiments is
5 intended to illustrate without limitation the present invention.
Tt is understood that changes and variations can be made therein
with departing from the scope of the invention which is defined in
the following claims.
